The authors present a clinical, pathological, and bacteriological investigation of pneumonias and other respiratory infections occurring with influenza and measles in military camps. They document epidemic influenza waves and corresponding rises in pneumonia, compare bacterial types isolated from stable camp populations versus newly drafted recruits, and correlate measles with unusually fatal secondary pneumonia. The report details timing of outbreaks, pathological findings, and microbiological patterns suggesting influenza and measles as major predisposing factors for severe lower respiratory infection, and emphasizes the variable etiology and high mortality of pneumonia in epidemic conditions.